World Water Safety
INTERNATIONAL LIFE SAVING FEDERATION
Gemeenteplein 26 – 3010 Leuven – Belgium
Tel: (32.16) 89.60.60 – Fax: (32.16) 89.70.70
E-mail: ils.hq@telenet.be - Web: www.ilsf.org
MEDICAL POSITION STATEMENT - MPS 18
EATING BEFORE SWIMMING
BACKGROUND
There is a longstanding advice that one should wait after eating before swimming. Often an hour of
wait is recommended. This review is conducted to evaluate the evidence that eating is a risk factor for
drowning and that waiting to swim after eating will decrease this risk.
Question:
Is there evidence that persons who have eaten recently have increased risk (over that of the general
population) to participate in bathing, recreation, instruction and competition on and in-water activity?
STATEMENT
There is no evidence that eating before swimming increases risk for drowning. While eating has been
associated with nausea, vomiting, and abdominal pain, the causal relationship between these
phenomena and drowning risk has not been reported nor well studied. Therefore, recommendations
on amounts, timing, and food type when eating prior to swimming or water activities cannot be based
on scientific evidence.
LITERATURE REVIEW
Conducted by Dr Linda Quan MD December 2013

Databases searched included: PubMed, Ovid Medline and OldMedline, CINAHL, Cochrane
Database of Systematic Reviews, UpToDate, MDConsult, JSTOR, Academic Search Complete,
Google Scholar, Google Books, Google Web Search, ERIC, SPORTDiscus, and Physical
Education Index.

Dates searched for publications from 1960 to the present (October, 2013)

Keywords used included:
Drowning, Drown, Drowned, Near drowning,
Swim, swimming, swam
Eat, eating, ate
Meal, nutrients, nutrition,
Digest, digested, digestion
Gut, gut action
Exercise
Water, aquatics

Human studies, in English
International Life Saving Federation
Medical Position Statement – MPS-18. Eating Before Swimming
Page 2
LEVEL OF EVIDENCE
For each article/source from step 1, assigned a level of evidence—based on study design and
methodology.
Level of
Evidence
Level 1
Level 2
Level 3
Level 4
Level 5
Level 6
Level 7
Level 8
Definitions (See manuscript for full details)
Randomized clinical trials or meta-analyses of multiple clinical trials with substantial
treatment effects
Randomized clinical trials with smaller or less significant treatment effects
Prospective, controlled, non-randomized, cohort studies
Historic, non-randomized, cohort or case-control studies
Case series: patients compiled in serial fashion, lacking a control group
Animal studies or mechanical model studies
Extrapolations from existing data collected for other purposes, theoretical analyses
Rational conjecture (common sense); common practices accepted before evidencebased guidelines
REFERENCES
Published, refereed journal articles
Quan’s comments/Level of Evidence (LOE)
1.Singer RN, Neeves RE. Effect of food
consumption on 200-yard freestyle swim
performance. Res Q. 1968;39(2):355-60.
No abdominal pain at ½, 1, 2 hours post eating large
meal pre competition in swimmers. LOE 3
2. Asprey G, Alley L, and Tuttle W. Effect of
eating at various times on subsequent
performances in the one-mile freestyle swim.
Res Q. 1968;39(2):231-4.
No abdominal pain/cramp in fed and non-fed swimmers.
LOE 3
3. Ball J. Effect of eating at various times on
subsequent performances in swimming.
No cramps/pain/difference in swimming 1,2, etc hours
after eating. LOE 3
4. Brouns F., Beckers E. Is the gut an athletic
organ? Digestion, absorption and exercise.
Sports Med. 1993;15(4):242-57
Review of lit: Pre-exercise ingestion of foods rich in
dietary fibre, fat and protein, as well as strongly
hypertonic drinks, may cause upper GI symptoms such
as stomach ache, vomiting and reflux or heartburn abd
pain but not distress with exercise.
5. Kibayashi K., Shimada R., Nakao K. Frequent
detection of stomach contents in accidental
drowning. Med Sci Law 2011;51(3):161-3.
Describes high frequency of food contents in drowning
victims which is higher than frequency in suicide victims.
While this is only study attempting to evaluate
relationship between eating and drowning death, as a
case: control study, its methodology is very problematic.
By using suicides as controls it has chosen a population
that is biased, one that by definition of depression is
probably least likely to eat and therefore not
representative of the general population. What they have
shown is that drowning victims are more likely to eat
than suicides but not that the eating caused the
drowning. LOE 4
6. Pfeiffer B., Stellingwerff T., Hodgson AB.
Randell R., Pottgen K. Res P. Jeukendrup AE.
High carb intake increases nausea and flatulence but
improves performance in marathon runners. LOE 5
International Life Saving Federation
Medical Position Statement – MPS-18. Eating Before Swimming
Page 3
Nutritional intake and gastrointestinal problems
during competitive endurance events. Medicine
& Science in Sports & Exercise. 2012;
44(2):344-51.
7. Morton DP, Richards D, Callister R.
Epidemiology of exercise-related transient
abdominal pain at the Sydney City to Surf
community run.
J Sci Med Sport. 2005; Jun;8(2):152-62.
Questionnaire survey, subject to recall bias. Describes
characteristics of abd pain in runners in a competition
setting. Abd pain more common in runners than walkers
and more likely after a large meal. Abdominal pain is a
problem in competitive swimmers. Exercise associated
transient abdominal pain (ETAP) LOE 5
Key organisations’ drowning prevention/water safety recommendations did not describe dangers of
nor prescribe any warnings regarding eating and swimming/water activities:

American Academy of Pediatrics- Committee on Injury Violence, and Poison Prevention, Weiss J.
Prevention of Drowning. Pediatrics. 2010;126(1):e253-262

CDC - Injury - Water-Related Injuries Fact Sheet. Available at: Accessed December 18, 2013)
http://www.cdc.gov/HomeandRecreationalSafety/Water-Safety/waterinjuries-factsheet.html

World Health Organization - WHO | Drowning. Available at:
http://www.who.int/mediacentre/factsheets/fs347/en/ [Accessed December 18, 2013].
Websites [Accessed December 5, 2013].
Searched for “swimming after eating”, “eating before swimming”, “eating and swimming”, “eating and
drowning”
http://www.snopes.com/oldwives/hourwait.asp Swimming myth
www.dukehealth.org: Myth or Fact: Wait 30 minutes after eating to go swimming
http://www.medicinenet.com/script/main/art.asp?articlekey=47368 Debunking summer health
myths
http://health.discovery.com/videos/dr-know-swimming-after-eating.html Discovery Health Video
http://health.howstuffworks.com/mental-health/human-nature/health-myths/swimming-aftereating.htm. Discovery Health. DO YOU REALLY HAVE TO WAIT AN HOUR AFTER BEFORE
SWIMMING? Old wives tale http://www.nytimes.com/2005/06/28/health/28real.html?_r=0
REALLY?
The Claim: Never Swim After Eating Top of Form
ANAHAD O'CONNOR Published: June 28, 2005. The food to avoid is alcohol.
http://www.mayoclinic.com/health/childrens-health/CC00003. Children's swimming: Keep health
risks at bay. “It's OK to swim immediately after a light meal or snack. If your child feels lethargic
after eating a heavy meal, encourage him or her to take a break before swimming. “
http/www.bbc.com/future/story/ 20130401-can-you-swim-an-hour-just-after-eating? BBC.
Medical Myths Should you wait an hour after eating until swimming?
SUMMARY
There is little published scientific literature or even general information on the effects of eating before
swimming. The two swim studies, both conducted in the 1960’s, showed no effect on swimming
performance and minimal side effects at several different time intervals after a meal. No reported
cases of eating before swimming causing or contributing to fatal or nonfatal drowning are reported in
any of the literature searched.
International Life Saving Federation
Medical Position Statement – MPS-18. Eating Before Swimming
Page 4
Research generally shows that food consumption prior and during athletic endeavors improves
performance. However, there is a small body of research on a condition called ETAP, exercise related
transient abdominal pain which is mostly reported among runners and is not debilitating nor severe.
Evaluation of liquid and food intake shows that the condition may occur more frequently in runners
who consumed high carbohydrate drinks. No significant symptoms were reported in any of the studies.
No research, major medical or water safety organizations make any recommendations to wait before
swimming after eating.
RECOMMENDATIONS
Food intake restrictions prior to swimming are unfounded. Class II Recommendation
Class of Recommendation selected from these summary definitions.
CLASS
Class I
Definitely recommended.
Definitive,
excellent evidence provides
support.
Class II: Acceptable and
useful
• Class IIa: Acceptable and
useful
Good evidence provides
support
• Class IIb: Acceptable
and useful
Fair evidence provides
support
Class III
Not acceptable, not useful,
may be harmful
Indeterminate
CLINICAL DEFINITION
• Always acceptable, safe
• Definitely useful
• Proven in both efficacy &
effectiveness
• Must be used in the intended
manner for
proper clinical indications.
• Safe, acceptable
• Clinically useful
• Not yet confirmed definitively
• Safe, acceptable
• Clinically useful
• Considered treatments of
choice
• Safe, acceptable
• Clinically useful
• Considered optional or
alternative
treatments
• Unacceptable
• Not useful clinically
• May be harmful.
• Research just getting started.
• Continuing area of research
• No recommendations until
further research
REQUIRED LEVEL OF EVIDENCE
• One or more Level 1 studies are
present (with rare exceptions)
• Study results consistently positive
and compelling
• Most evidence is positive
• Level 1 studies are absent, or
inconsistent, or lack power
• No evidence of harm
• Generally higher levels of evidence
• Results are consistently positive
• Generally lower or intermediate levels
of evidence
• Generally, but not consistently,
positive results
• No positive high level data
• Some studies suggest or confirm
harm.
• Minimal evidence is available
• Higher studies in progress
• Results inconsistent, contradictory
• Results not compelling
POTENTIAL CONFLICT OF INTEREST STATEMENT:
The author has no conflict of interest with the stakeholder industry, technology, persons or
organisations that are identified and/or impacted by the position statement.
APPROVAL
Position Statement approved by the ILS Board of Directors on 16/09/2014.